Effects Of Electrostimulation On Mitochondria In Atrophy Rat Skeletal Muscles Of Disuse: Mitochondrial Biogenesis And Respiratory Function

Objective:This article focuses on establishing the model of muscular atrophy of disuse and recovering by electrostimulation. We try to investigate the mitochondrial biogenesis and respiratory function in skeletal muscles of rat. Further more, we study the effects of electrostimulation on mitochondrial biogenesis and respiratory function in skeletal muscles of rat after the muscular atrophy of disuse occurred.Methods:The SD male rats were devided into four groups:contrl group(A), atrophy group(B), every other day-stimulate group(C), everyday-stimulate group(D). The rats in the last three groups were colligated by tailor-made mould. Meanwhile, the rats in the last two groups were stimulated by electricity for everyday and every other day. After three weeks training, we measured the body weight, wet weight/body weight, maximal strength, average strength. We tested mRNA of myosin heavy chain (I, IIa,IIx,IIb) by real-time PCR and the proteins of PGC-la and COXIV by Western Blot. This study also refers to the content of R3.R4, RCR and H2O2 in skeletal muscles of rats.Result:After three weeks training, the body weight of rats decrease and group C decrease obviously. Wet weight/body weight, maximal strength and average strength are lower in group B and D, while it is not sharp in group B. There are lower MHC I mRNA and higher MHC IIa, IIx, IIb mRNA after atrophy, and no differences in the last three groups. Compared with group A. the protein of PGC-lαand COXⅣare decrease. They are increase after stimulated by electricity. Rroup D is increase obviously. R3, R4, RCR is decrease in group B and increase in group C and D. There are more changes in group D for R3 and R4. There is the same level for RCR in the last three groups. The levels of H2O2 in group B and D are most of all. then group C is second, group A is last.Conclusion:1)The protein of PGC-la, COXⅣand RCR decrease after atrophy, it can prove mitochondrial biogenesis and respiratory function are weaken after atrophy.2) After electric stimulating, the protein of PGC-la, COXⅣand RCR are increase, it can prove mitochondrial biogenesis and respiratory function are enhance after training.3)Compared with group D, the protein of PGC-la, COXⅣand RCR are increase obviously in group C. Electric stimulating is more effecieny for preventing the atrophy of muscles.4) High quantity of stimulus may produce more H2O2, it can damage the cells of skeletal muscles, and be of no effect for preventing the atrophy of muscles. Only the right quantity of stimulus can be used.5) The consumption of ATP in red and white muscles are different. It hypothesize that the change of activity of PGC-lαand COXⅣmay change the synthetic amount of ATP in respiratory chain. At last, it may change the muscle fiber types.